Moscow Sobor of 1666–1667

The Moscow Sobor of 1666–1667 was a council of the Church of Russia, with representation from other patriarchates, convened in Moscow, Russia by Tsar Alexis of Russia. The business of the council was concerned mainly with Russian liturgical practices that were inconsistent with those of the Orthodox Churches on the eastern Mediterranean world.

The council officially established the reforms that had been brought forward during the patriarchate of Patr. Nikon and anathematized all those who opposed the changes to the old Russian books and rites made to comply with the Church's liturgical unity. Even the old Russian books and rites themselves were anathematized. Old Ritualists were condemned for refusing to comply with such liturgical changes as celebrating feast days on the same day as the rest of the Orthodox Churches, making the sign of the cross with three fingers instead of two, and not kneeling on Sundays.

One of the decisions during the sobor was a specific ban on a number of depictions of God the Father and the Holy Spirit, which then resulted in a whole range of other icons being placed on the forbidden list.[1]